Edge-sealing arrangement for air filter apparatus



E. SCHWARZ Oct. 25, 1966 EDGE-SEALING ARRANGEMENT FOR AIR FILTER APPARATUS Filed May 2, 1965 INVENTOR.

EDGAR SCHWARZ Q QQM ATTORNEY United States Patent 3,280,538 EDGE-SEALING ARRANGEMENT FOR AIR FILTER APPARATUS Edgar Schwarz, Louisville, Ky., assignor to American Air Filter Company, Inc., Louisville, Ky., a corporation of Delaware Filed May 2, 1963, Ser. No. 277,532 2 Claims. (Cl. 55-354) The present invention relates to automatic air filters and more particularly to automatic air filters of the type employing an elongated air cleaning web adapted to be progressively advanced longitudinally across an air stream passage to clean dirty air as it is passed through such passage.

The present invention finds particular applicability in those structures known in the art wherein a supply of filter medium such as filamentous fiber glass mat is furnished in a tightly wound, compressed condition on a roll mounted in a supply zone at one end of the filter, is Withdrawn from the roll and moved through an air cleaning zone in a resiliently expanded condition and finally directed into a discharge Zone at the opposite end of the filter where it is manipulated into a compact package for disposal. It is to be understood that the present invention is not to be considered as limited to the specific filter medium or structure aforedescribed, but that it can be utilized in any one of a number of known filter structures wherein any one of a number of known types of filter medium in web form is progressively advanced across an air stream passage to clean air as it passes through such passage.

Because of the nature of filter medium web and the structure which serves to advance it progressively across an air stream, a necking or width reducing of the web frequently occurs in the air stream with an accompanying loss of air seal along the edges of the structure. The present invention provides an economical and straightforward structural arrangement which minimizes such width distortion of the filter medium and its displacement from the edge seal without necessitating cumbersome additional structure which would increase manufacturing cost and which would present additional resistance to the air stream treated.

Various other features of the present invention will become obvious to one skilled in the art upon reading the disclosure set forth herein.

More particularly the present invention provides: in an air cleaning device of the type employing an elongated air cleaning web adapted to be progressively advanced longitudinally across an air stream passage, a pair of channel-shaped flange members, each of the flange members including a base leg and spaced upstream and downstream side legs extending integral with and generally normal to the base leg; the flange members being positioned in spaced relationship along opposite longitudinal edges of the air stream passage with their side legs inwardly directed toward the passage to engage in lapping relationship with the opposite longitudinal margins of the web to prevent the flow of uncleaned air therearound; and, aperture means extending along the upstream side legs of the channel-shaped flange members to permit a portion of the uncleaned air to pass therethrough to urge the longitudinal margins of the web against the downstream legs of the flange members and restrain the web against lateral displacement in the air stream passage.

It is to be understood that various changes can be made in the arrangement, form and construction of the apparatus disclosed herein without departing from the scope or spirit of the present invention.

Referring to the drawing which discloses one advantageous embodiment of the present invention:

FIGURE 1 is an elevational perspective view of a vertically disposed filter arrangement including the inventive apparatus; and,

FIGURE 2 is a horizonal cross-sectional view of the apparatus of FIGURE 1 taken in a plane passing through line 2-2 of FIGURE 1; and

FIGURE 3 is an enlarged view of a portion of the upstream side leg of a web-retaining channel of FIGURE 1.

Referring to FIGURE 1 of the drawing, a roll type filter housing 2 is disclosed in verticle position. Housing 2 includes top filter medium supply section 3, central air treating section 4 and bottom filter medium take-up section 6. Mounted in tightly wound form in supply section 3 is supply roll 7. Roll 7 can be comprised of a web of suitable filter medium material such as expansiblecompressible fiber glass material. This web is advanced incrementally from time-to-time into and through the central air treating section 4 which frames the air stream passage through which the air to be treated must flow. As the web is progressively advanced through central section 4 the web assumes its expanded thickness form in the air stream to filter contaminants. The web is then correspondingly progressively advanced to the take-up section 6 Where it is tightly wound up into a discharge roll 8 which can be ultimately thrown away or reconditioned. Suitable drive motor and Web metering controls, known in the art and not described in detail, can be utilized to advance the medium progressively in the manner aforedescribed.

It is to be noted that central section 4 includes along its opposite sides the longitudinally and vertically extending upright support members 5 secured at their ends to supply section 3 and take-up section 6. As can be seen in FIGURE 2 of the drawing, each upright support member 5 has fastened thereto in co-extending fashion therewith a channel-shaped flange member 11. Each channel-shaped flange member 11 includes a base leg 12 and spaced upstream and downstream side legs 13 and 14, respectively, extending integral with and generally normal to such base leg. Flange members 11 are positioned with their side legs 13 and 14 inwardly directed toward the air stream passage which the flange members frame to engage in lapping relationship with the opposite longitudinal margins of the web of filter medium so as to prevent the flow of uncleaned air therearound. As is known in the art, suitably spaced, vertically disposed media retaining rods 10 extend between sections 3 and 6 along the upstream face of the media and similarly disposed media retaining rods 15 extend between sections 3 and 6 along the downstream face of the media.

Provided in the upstream side leg 13 of each of flange members 11 is a plurality of spaced apertures 16. These apertures are arranged to extend longitudinally along the upstream side legs 13 from the supply section 3 to the take-up section 6. Advantageously, apertures 16 can be of one-fourth A) inch radius and can be spaced twelve (12) inches from their centers. It is to be understood that the present invention is not to be considered as limited to these aforedescribed dimensions but that the dimensions may vary in accordance with the general size of the structure, the filter medium to be used and the velocity of the air stream to be treated. Apertures 16 serve to permit a portion of the uncleaned air to be treated to pass through the upstream side legs 13 of the channel-shaped flange members 11 and through the filter medium engaging in the flange members, at the same time, urging the longitudinal marginal edges of the web against the downstream side legs 14 of the ch-annelshaped flange members to restrain the web against lateral displacement in the air stream passage. It is to be noted that the downstream side legs 14 have end portions 17 turned inwardly at an angle toward the upstream side legs 13. Thus, as can readily be seen in FIGURE 2, when the filter medium is urged against downstream side legs 14, the medium is compressed against the end portions 17 to further insure its restraint against lateral displacement in the air stream passage.

The invention claimed is:

1. Air cleaning apparatus comprising: a housing having an air cleaning web sheet material supply section at one end thereof; a web take-up section at the opposite end of said housing; and a flow-through gas treating section intermediate said supply and take-up section and defining a gas flow passage therethrough, said gas treating section including a pair of channel-shaped flange members, each of said flange members having a base leg and spaced upstream and downstream side legs extending integral with and generally normal to said base leg; said flange members being positioned in spaced relationship along and defining opposite longitudinal edges of said passage, said flange members extending from the supply section to the take-up section with said side legs thereof being inwardly directed toward said passage to engage in lapping relationship with the opposed longitudinal margins of said web to prevent flow of unclean air thercaround; and a plurality of spaced apertures extending longitudinally from said supply section to said take-up section along each of said upstream side legs of said channel-shaped flange members intermediate the respective edge portions thereof and the respective one of said base legs to permit a portion of the uncleaned air to pass therethrough to directly impinge upon the upstream face of said air cleaning web, urging the longitudinal margins of said web along the length thereof against said downstream legs of said flange members and restraining said web against lateral displacement in' said passage; and, web advancing means con- 4 structed and arranged for advancing portions of said web from said supply section to said take-up section and for causing relative motion between said web and said flange members; said base leg, upstream leg and downstream leg of each flange member defining a member having a substantially U-shaped cross-section, said web substantially filling said U-shaped cross-section so that the edge of the web disposed therein extends substantially beyond said spaced aperatures toward said base leg.

2. The apparatus of claim 1, said downstream side legs of said flange members having their end portions turned inwardly at an angle toward saidupstream side legs to permit the medium to compress against the inturned portion, further restraining said web against lateral displacement.

References Cited by the Examiner UNITED STATES PATENTS HARRY B.'THORNTON, Primary Examiner.

D. TALBERT, Assistant Examiner. 

1. AIR CLEANING APPARATUS COMPRISING: A HOUSING HAVING AN AIR CLEANING WEB SHEET MATERIAL SUPPLY SECTION AT ONE END THEREOF; A WEB TAKE-UP SECTION AT THE OPPOSITE END OF SAID HOUSING; AND A FLOW-THROUGH GAS TREATING SECTION INTERMEDIATE SAID SUPPLY AND TAKE-UP SECTION AN DEFINING A GAS FLOW PASSAGE THERETHROUGH, SAID GAS TREATING SECTION INCLUDING A PAIR OF CHANNEL-SHAPED FLANGE MEMBERS, EACH OF SAID FLANGE MEMBERS HAVING A BASE LEG AND SPACED UPSTREAM AND DOWNSTREAM SIDE LEGS EXTENDING INTEGRAL WITH AND GENERALLY NORMAL TO SAID BASE LEG; SAID FLANGE MEMBERS BEING POSITIONED IN SPACED RELATIONSHIP ALONG AND DEFINING OPPOSITE LONGITUDINAL EDGES OF SAID PASSAGE, SAID FLANGE MEMBERS EXTENDING FROM THE SUPPLY SECTION TO THE TAKE-UP SECTION WITH SAID LEGS THEREOF BEING INWARDLY DIRECTED TOWARD SAID PASSAGE TO ENGAGE IN LAPPING RELATION WITH THE OPPOSED LONGITUDINAL MARGINS OF SAID WEB TO PREVENT FLOW OF UNCLEAN AIR THEREAROUND; AND A PLURALITY OF SPACED APERTURES EXTENDING LONGITUDINALLY FROM SAID SUPPLY SECTION TO SAID TAKE-UP SECTION ALONG EACH OF SAID UPSTREAM SIDE LEGS OF SAID CHANNEL-SHAPED FLANGE MEMBERS INTERMEDIATE THE RESPECTIVE EDGE PORTIONS THEREOF AND 